A linter for judgment calls: keeping a codebase clean with a decision model
Most of what makes a codebase rot is not hard to describe. A comment that records who asked for a change instead of why the code is that way. Sample data that leaks into a production screen. A test that passes because it skipped. A "temporary" per-record override that quietly becomes a second source of truth. Every team can write these rules down. The problem is that most of them cannot be expressed as a regex, so they live in a wiki, get enforced by whoever happens to be reviewing, and drift.
Jev, TypeSafe's "System One" model, turns out to be a good fit for exactly this gap. It does not generate text. You hand it a small piece of state and a set of typed yes/no questions, and it returns a calibrated probability for each. That shape is what a linter for judgment calls needs.
